Sectionable cassette and embedding frame with connectors, and methods for preparing biopsy tissue samples

ABSTRACT

A method for preparing one or more biopsy tissue samples for histological examination includes positioning a tissue sample in a tissue cassette, closing a peripheral portion of a frame including a cassette lid, and moving the lid and the tissue cassette from a first position to a second position. The tissue cassette is coupled to a frame by a frame-cassette connector and moving the lid and the tissue cassette from the first position to the second position includes breaking the frame-cassette connector. The tissue cassette has a recess including at least one side wall and a bottom wall and is formed of a first material that can be successfully sectioned in a microtome. In the second position, the bottom wall and at least a portion of the side wall extend downwardly beyond a bottom edge of the frame for sectioning in the microtome.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.16/680,601, filed Nov. 12, 2019, the disclosure of which is herebyincorporated by reference herein in its entirety.

TECHNICAL FIELD

The present invention generally relates to supports for handling andembedding tissue samples for pathological analysis and, moreparticularly, to microtome sectionable supports which can receive one ormore tissue samples and a support frame having a tissue immobilizinglid.

BACKGROUND

To accurately diagnose various tissue diseases and conditions, medicalpersonnel must remove one or more samples of tissue from the body of apatient. This process of harvesting tissue from the body is known as abiopsy. Once the tissue sample or samples are removed and sent to apathology laboratory, the tissue will go through a series of proceduresperformed by a histotechnician and, ultimately, a pathologist, in orderto diagnose one or more conditions associated with the tissue. Thepresent invention generally relates to those procedures that arenormally performed by the histotechnician to prepare the tissue sampleor samples into slides that may be analyzed under a microscope by thepathologist.

Although the singular term “sample” is used throughout thisspecification, it should be understood that this term likewiseencompasses plural “samples” as well. Once a tissue sample is removedfrom the body of a patient, it is typically placed into a specimencontainer containing a tissue fixative solution and then the containeris transported to a pathology laboratory. The tissue will undergo aprocess known as “grossing-in” in the pathology lab during which ahistotechnician will retrieve the tissue sample from the container,typically cut the tissue into appropriate sizes for tissue processing,place individual samples into the appropriate sized small plastic tissuecassettes, and assign tracking numbers to each cassette. The assignmentof tracking numbers is usually done by printing the tracking number onthe cassette, or onto a label which is then applied to the cassette.These tracking numbers are then logged into a tracking system used inthe laboratory. For the smallest tissue samples, which may only bescrapings, the cassette includes fine mesh openings on the sides andbottoms. In other situations involving very small tissue samples, thesamples are placed into a bag that resembles a tea bag that prevents thesmallest tissue samples from escaping. Larger tissue samples are placedinto cassettes having somewhat larger slotted openings which arenevertheless smaller than the tissue sample inside the cassette.

The cassettes are then placed into a stainless steel perforated basketand run through a tissue processing machine, often overnight. Thismachine uses a combination of vacuum, heat, and liquid reagents orchemicals to remove the interstitial fluids within the tissue. Once thefluids have been removed from the tissue samples, the processing machineimmerses the tissues samples in a bath of a hardenable material such asmolten paraffin (i.e., a form of wax) so that the interstices in thetissue are replaced with paraffin. The histotechnician then removes thebasket from the machine and removes the individual tissue cassettes. Ina conventional procedure practiced for many years, the histotechnicianindividually removes the tissue sample from each cassette. Thehistotechnician must carefully orient the tissue sample, based on tissuetype, into a stainless steel base mold that is roughly the size of thetissue cassette and is partially filled with molten paraffin. The tissuesample must be manually held, typically using forceps, against thebottom of the mold. If it is not, this could compromise the ability tomake proper slices of the tissue sample later in a microtome. The moltenparaffin is then rapidly cooled on a refrigerated plate, which may be athermal electric cooler (TEC), to partially solidify the paraffinthereby holding the tissue sample in the proper orientation against thebottom of the mold.

The cassette is then placed on top of the base mold and an embeddingmaterial, which is also typically paraffin wax, is poured through theopened top of the cassette into the base mold. The cassette changes itsfunction at this point in the procedure from a tissue holding componentto a fixture type device for mounting in the microtome and makingshavings or slices from the solidified paraffin block (containing thetissue sample) in the microtome. The base mold is chilled until all ofthe molten paraffin has hardened and the histotechnician removes thestainless steel base mold from the block of paraffin and embeddedtissue. The tissue sample is thus embedded within a rectangular block ofhard paraffin with a plastic tissue cassette on the opposite side. Asmentioned, the cassette may then be used as a holder or fixture in thechuck of the microtome. As with the tissue processing machine, theembedding process is accomplished in a batch fashion during which anaverage histotechnician may process approximately 40 to 60 cassettes perhour into blocks of embedded tissue.

The blocks of hardened paraffin containing the embedded tissue samplesare then ready to be sliced into extremely thin sections for placementon a microscope slide. The histotechnician mounts the embedded tissueblock in a chuck on the microtome sized to accept the side of the blockthat has the embedded plastic cassette. The histotechnician can thenbegin slicing the paraffin block which has the tissue sample embeddedopposite to the plastic cassette surface. This yields a ribbon ofindividual slices of the tissue embedded in the hardened paraffin. Theaction of the microtome causes the individual slices to stick togetherwhen done properly and, subsequently, these very thin ribbons of slicesare floated into a water bath and a glass slide is carefully placedunderneath the slice. Each slice, with the thin sectioned tissue sampleembedded therein, is then adhered to the top of a microscope slide. Whenthe histotechnician has enough slides from the tissue sample, the slidesare placed into an automatic staining machine. The staining machine goesthrough a series of infiltrating steps to stain the different tissue andcells of the slide different colors. This helps the pathologist identifydifferent structures and makes it easier to find any abnormalities inthe tissue. After the staining procedure is complete, the slides arecover slipped and prepared for the pathologist to place under amicroscope for analysis.

Based on the summary of the procedure provided above, it will beappreciated that conventional tissue sample handling and processing is avery labor-intensive process involving several manual steps performed bya histotechnician. Thus, repetitive stress injuries such as carpaltunnel syndrome are prevalent. This is especially true with the tissuesample embedding process. These multiple manual operations and repeatedtissue handling increase the likelihood of human error and, moreover,require highly trained and skilled histotechnicians to ensure that thetissue samples ultimately adhered to the slides for analysis by thepathologist are in an optimum condition and orientation to make accuratediagnoses.

U.S. Pat. No. 5,817,032 (the '032 patent), U.S. Pat. Nos. 7,156,814,7,179,424, 7,722,810, 7,776,274 and 8,383,067 and U.S. PatentApplication Publication No. 2018/0156701 disclose various improvementsto this area of technology, including new manners of holding tissuesamples during the grossing in, embedding, and microtome or slicingprocedures. The disclosures of the '032 patent, U.S. Pat. Nos.7,156,814, 7,179,424, 7,722,810, 7,776,274 8,383,067 and 2018/0156701are hereby fully incorporated by reference herein. For example, the '032patent relates to a tissue trapping and supporting device, which may bea cassette, and which may be successfully sectioned using a microtome.When such a cassette is used, the tissue sample is immobilized withinthe cassette and subjected to the process for replacing tissue fluidswith paraffin. Then, both the tissue sample and the cassette are slicedat the same time for later mounting on microscope slides. Because thetissue sample is never removed from the cassette from the time it isprocessed in the tissue processing machine to the time that it is cut orsliced with the microtome, a significant amount of handling time issaved. Moreover, the chance for human error or tissue loss issignificantly reduced due to the elimination of separate tissue handlingsteps. The '032 patent and the other above-incorporated patentproperties also generally disclose further improvements that help toautomate the overall process and, in conjunction with the novel tissuesupports (e.g., cassettes), can even further reduce the handling stepsduring the entire procedure and make the procedure more reliable.

Various drawbacks of current procedures and limits on innovation exist.For instance, improvements to the outer form of the cassette and frameare bounded by existing limits of histopathology lab equipment such astissue processing retorts, and “input devices” for tissue processors,embedding stations, printers, and microtomes. Many of these processesare integrated with systems and machines for automation of the steps androbotic handling further limiting the potential for innovation.Additionally, costs for materials have been rising in recent years,especially for the fluoropolymer (FEP/PFA) sectionable plastics usefulin sectionable cassettes. Each cassette is essentially consumed by thesectioning procedure, which adds to the cost of the pathology procedure.Further, because the sectionable FEP/PFA material is not rigid, it maybe utilized for some components (e.g., the cassette), while othercomponents (e.g., frames) may be constructed from harder or more rigidmaterials.

In spite of the various advances made in this field, there is a need foradditional improvements related to cassettes and embedding frames,particularly for cassette and frame assemblies including some componentsformed of relatively soft materials (e.g., sectionable plastics) thatare coupled to other components formed of harder materials.

SUMMARY

In accordance with one embodiment, a histologic tissue sample supportdevice includes a tissue cassette having a recess including at least oneside wall and a bottom wall. The tissue cassette is formed of a firstmaterial that can be successfully sectioned in a microtome and isresistant to degradation from solvents and chemicals used to fix,process and stain tissue. The device further includes a frame includinga bottom edge, the frame formed of a second material different from thefirst material and more rigid than the first material. The tissuecassette is coupled to the frame by a frame-cassette connector includinga first retaining structure formed integrally with the frame extendingat least partway through a second retaining structure formed integrallywith the cassette. The device further includes a lid coupled to theframe. The lid and the tissue cassette are capable of moving from afirst position to a second position with respect to the frame. In thesecond position, the bottom wall and at least a portion of the side wallextend downwardly beyond the bottom edge of the frame for sectioning inthe microtome. The frame is capable of being decoupled from the cassetteby separating the frame-cassette connector.

In additional or alternative aspects, the first retaining structure mayinclude a pin formed integrally with the frame. The second retainingstructure may include a flange formed integrally with the cassette.Moving the lid and the tissue cassette from the first position to thesecond position may break the flange formed integrally with thecassette. The flange formed integrally with the cassette may include astress riser arranged to encourage breakage of the flange formedintegrally with the cassette when the lid and the tissue cassette aremoved from the first position to the second position. The frame mayinclude a plurality of outer walls extending generally upward from thebottom edge. The pin formed integrally with the frame may be disposed ona tab extending generally laterally inwardly from one of the pluralityof outer walls. The pin formed integrally with the frame may extendgenerally upwardly from the tab. The pin formed integrally with theframe may extend generally downwardly from the tab. The tab extendingfrom one of the plurality of outer walls may be pivotably coupled to theone of the plurality of outer walls. The pin formed integrally with theframe may have a generally circular cross section. The pin formedintegrally with the frame may include a base, a tip having a tip width,and a shaft having a shaft width and extending from the base to the tip,and the tip width may be greater than the shaft width.

In additional or alternative aspects, the lid may be coupled to theframe by a lid-frame connector comprising a third retaining structureformed integrally with a peripheral portion of the frame extending atleast partway through a fourth retaining structure formed integrallywith the lid. The lid may be capable of being decoupled from theperipheral portion of the frame by separating the lid-frame connector.The third retaining structure may include a pin formed integrally withthe peripheral portion of the frame. The fourth retaining structure mayinclude a flange formed integrally with the lid. Moving the lid and thetissue cassette from the first position to the second position may breakthe flange formed integrally with the lid. The lid may be formed of thefirst material. The peripheral portion of the frame may include aplurality of peripheral walls surrounding the lid. The pin formedintegrally with the peripheral portion may be disposed on a tabextending generally laterally inwardly from one of the plurality ofperipheral walls. When the lid is in a closed configuration, the pinformed integrally with the peripheral portion may extend generallydownwardly from the tab. When the lid is in a closed configuration, thepin formed integrally with the peripheral portion may extend generallyupwardly from the tab. The tab extending from one of the plurality ofperipheral walls may be pivotably coupled to the one of the plurality ofperipheral walls. The pin formed integrally with the peripheral portionmay have a generally circular cross section.

In additional or alternative aspects, the tissue cassette may include acassette closure element and the lid may include a lid closure element,the cassette closure element and the lid closure element beingconfigured, when engaged, to secure the lid to the tissue cassette. Oneof the cassette closure element and the lid closure element may includea first connector disposed on a first extending arm and the other of thecassette closure element and the lid closure element may include asecond connector, the first connector engaging the second connector tosecure the lid to the tissue cassette. The lid closure element mayinclude the first connector disposed on the first extending arm and thecassette closure element may include the second connector. The lidclosure element may include a third connector disposed on a secondextending arm, the first extending arm and the second extending armprojecting generally downwardly from the lid when the lid is in a closedconfiguration on the cassette, the first extending arm and the secondextending arm disposed on the lid in a spaced-apart, opposed arrangementsuch that the first connector faces away from the third connector. Thecassette closure element may include a fourth connector arranged toengage the third connector, the second connector and the fourthconnector being generally laterally oriented.

In additional or alternative aspects, the lid closure element mayinclude a third connector disposed on a second extending arm, the firstextending arm and the second extending arm projecting generallydownwardly from the lid when the lid is in a closed configuration on thecassette, the first extending arm and the second extending arm disposedon the lid in an opposed arrangement such that the first connector facestowards the third connector. The second connector may be orientedgenerally laterally and may be arranged to engage the first connectorand the third connector. The frame may include a plurality of outerwalls extending generally upward from the bottom edge and a peripheralportion coupled to one of the plurality of outer walls by a hinge. Thetissue cassette may be coupled to one of the plurality of outer wallsand the lid may be coupled to the peripheral portion. At least one ofthe plurality of outer walls may include a frame closure element and theperipheral portion may include a peripheral portion closure element, theframe closure element and the peripheral portion closure element beingconfigured, when engaged in a closed configuration, to secure theperipheral portion to the plurality of outer walls. One of the frameclosure element and the peripheral portion closure element may include alatch disposed on an extending arm and the other of the frame closureelement and the peripheral portion closure element may include a flange,the latch engaging the flange to secure the peripheral portion to theplurality of outer walls in the closed configuration. The peripheralportion closure element may include the latch disposed on the extendingarm and the frame closure element may include the flange. The extendingarm may project generally downwardly from the peripheral portion in theclosed configuration and the flange may be oriented generally laterally.

In additional or alternative aspects, the lid may include a platenconfigured to be received within the recess of the tissue cassette, theplaten being mounted to a peripheral portion of the lid by a pluralityof biasing members arranged to bias the platen toward the bottom wall ofthe recess when the lid is in a closed configuration. The biasingmembers may be disposed in at least one of a generally helicalarrangement and a generally perpendicular arrangement between the platenand the peripheral portion of the lid.

In accordance with another embodiment, a histologic tissue samplesupport device includes a tissue cassette having a recess including atleast one side wall and a bottom wall. The tissue cassette is formed ofa first material that can be successfully sectioned in a microtome andis resistant to degradation from solvents and chemicals used to fix,process and stain tissue. The device further includes a frame includinga bottom edge. The tissue cassette is movably coupled to the frame. Thedevice further includes a lid coupled to the frame. The lid includes aplaten configured to be received within the recess of the tissuecassette. The platen is mounted to a peripheral portion of the lid by aplurality of biasing members arranged to bias the platen toward thebottom wall of the recess when the lid is in a closed configuration. Thelid and the tissue cassette are capable of moving from a first positionto a second position with respect to the frame. In the second position,the bottom wall and at least a portion of the side wall extend beyondthe bottom edge of the frame for sectioning in the microtome.

In additional or alternative aspects, the biasing members may bedisposed in a generally helical arrangement between the platen and theperipheral portion of the lid. The biasing members may be disposed in agenerally perpendicular arrangement between the platen and theperipheral portion of the lid. The platen may include a plurality oftines extending toward the bottom wall of the recess when the lid is inthe closed configuration. The lid may be formed of the first material.The frame may be formed of a second material different from the firstmaterial and more rigid than the first material, the tissue cassettebeing coupled to the frame by a frame-cassette connector comprising afirst retaining structure formed integrally with the frame extendingthrough a second retaining structure formed integrally with thecassette. The first retaining structure may include a pin formedintegrally with the frame and the second retaining structure may includea flange formed integrally with the cassette. The lid may be coupled tothe frame by a lid-frame connector comprising a first retainingstructure formed integrally with a peripheral portion of the frameextending at least partway through a second retaining structure formedintegrally with the lid. The lid may be capable of being decoupled fromthe peripheral portion of the frame by separating the lid-frameconnector. The first retaining structure may include a pin formedintegrally with the peripheral portion of the frame. The secondretaining structure may include a flange formed integrally with the lid.

The invention further provides a method for manufacturing an apparatusfor holding a histologic tissue sample while sectioning the tissuesample in a microtome. The method includes molding a tissue cassettehaving a recess including at least one side wall and a bottom wall, thetissue cassette being formed of a first material that can besuccessfully sectioned in a microtome and is resistant to degradationfrom solvents and chemicals used to fix, process and stain tissue. Themethod further includes molding a frame including a bottom edge, theframe being formed of a second material different from the firstmaterial and more rigid than the first material. The method furtherincludes coupling the tissue cassette to the frame by assembling aframe-cassette connector comprising a first retaining structure formedintegrally with the frame extending at least partway through a secondretaining structure formed integrally with the cassette. The cassette iscapable of being decoupled from the frame by separating theframe-cassette connector.

In additional or alternative aspects, the first retaining structure mayinclude a pin formed integrally with the frame. The second retainingstructure may include a flange formed integrally with the cassette.Assembling the frame-cassette connector may include forming a mushroomhead shaped tip on the pin formed integrally with the frame to securethe flange formed integrally with the cassette on the pin formedintegrally with the frame. Forming the mushroom head shaped tip on thepin may include deforming the pin to form the mushroom head shaped tip.Deforming the pin to form the mushroom head shaped tip may include usinga tool to form the mushroom head shaped tip when the pin is at atemperature above room temperature and below a melting temperature ofthe second material. Assembling the frame-cassette connector may includeat least one of (1) assembling separately molded components, (2)co-molding the frame and the cassette, and (3) insert molding the frameand the cassette. The method may further include molding a lid; andcoupling the lid to the frame by assembling a lid-frame connectorcomprising a third retaining structure formed integrally with aperipheral portion of the frame extending through a fourth retainingstructure formed integrally with the lid. The lid may be capable ofbeing decoupled from the peripheral portion of the frame by separatingthe lid-frame connector. The third retaining structure may include a pinformed integrally with the peripheral portion of the frame. The fourthretaining structure may include a flange formed integrally with the lid.Assembling the lid-frame connector may include at least one of (1)assembling separately molded components, (2) co-molding the lid and theframe, and (3) insert molding the lid and the frame.

The invention further provides a method for preparing one or more biopsytissue samples for histological examination. The method includespositioning a tissue sample in a tissue cassette having a recessincluding at least one side wall and a bottom wall, the tissue cassetteformed of a first material that can be successfully sectioned in amicrotome and is resistant to degradation from solvents and chemicalsused to fix, process and stain tissue, the tissue cassette beingdisposed in a frame including a bottom edge, the tissue cassette beingcoupled to the frame by a frame-cassette connector including a firstretaining structure formed integrally with the frame extending through asecond retaining structure formed integrally with the cassette. Themethod further includes closing a peripheral portion of the frame, theperipheral portion of the frame including a cassette lid disposedtherein. The method further includes moving the lid and the tissuecassette a from a first position to a second position with respect tothe frame including breaking the frame-cassette connector. In the secondposition, the bottom wall and at least a portion of the side wall extenddownwardly beyond the bottom edge of the frame for sectioning in themicrotome.

In additional or alternative aspects, the first retaining structure mayinclude a pin formed integrally with the frame. The second retainingstructure may include a flange formed integrally with the cassette. Themoving operation may include breaking a lid-frame connector including athird retaining structure formed integrally with the peripheral portionof the frame extending through a fourth retaining structure formedintegrally with the lid. The third retaining structure may include a pinformed integrally with the peripheral portion of the frame. The fourthretaining structure may include a flange formed integrally with the lid.The frame may be formed of a second material different from the firstmaterial and more rigid than the first material; and the lid may beformed of the first material. The closing operation may include securingthe tissue sample in the recess using a platen mounted to the lid by aplurality of biasing members arranged to bias the platen toward thebottom wall of the recess.

Various additional features and advantages of the invention will becomemore apparent to those of ordinary skill in the art upon review of thefollowing detailed description of the illustrative embodiments taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an assembly according to one embodiment.

FIG. 1A is an exploded perspective view of the assembly of FIG. 1 .

FIG. 2 is a top view of the assembly of FIG. 1 showing the tissuecassette and the frame in the open position ready to accept tissue inthe tissue cassette.

FIG. 3A is a cross sectional view of the assembly of FIG. 1 takengenerally along line 3-3 of FIG. 2 showing the tissue cassette and theframe in a partially closed position with tissue in the tissue cassette.

FIG. 3B is a cross sectional view similar to FIG. 3A but showing theperipheral portion of the frame and the lid in the closed position.

FIG. 3C is a cross sectional view similar to FIG. 3B but showing theassembly in the closed position. A portion is further broken away toshow details of the connector.

FIG. 3D is a cross sectional similar to FIG. 3C but showing the assemblyin a staged or second position where the lid is separated from theperipheral portion of the frame and a portion of the tissue cassette isready to be embedded and then sectioned in a microtome.

FIG. 4A is a cross sectional view of the assembly of FIG. 1 takengenerally along line 4A-4A of FIG. 2 and in the open position.

FIG. 4B is a cross sectional view similar to FIG. 4A but showing theperipheral portion of the frame and the lid in the closed position.

FIG. 4C is a cross sectional view similar to FIG. 4B but showing theassembly in the staged or second position where the lid is separatedfrom the peripheral portion of the frame.

FIGS. 5A-5D are detailed cross sectional views of the assembly of FIG. 1taken generally along line 5-5 of FIG. 2 showing steps of an assemblyprocess.

FIG. 5E is a detailed cross sectional view of the assembly of FIG. 1taken generally along line 5E-5E of FIG. 2 with the lid in the closedposition.

FIGS. 6A-6D are cross sectional views of an alternative pin/flangeconnector showing steps of an assembly process.

FIGS. 7A-7C are cross sectional views of another alternative pinconnector showing steps of an assembly process.

FIGS. 7D-7F are cross sectional views of another alternative pinconnector showing steps of an assembly process.

FIG. 8 is a perspective view of an alternative assembly according toanother embodiment.

FIG. 9 is a top view of the assembly of FIG. 8 showing the tissuecassette and the frame in the open position ready to accept tissue inthe tissue cassette.

FIG. 10A is a cross sectional perspective view of the assembly of FIG. 8taken generally along line 10A-10A of FIG. 9 and in the open position.

FIG. 10B is a cross sectional perspective view similar to FIG. 10A butshowing the peripheral portion of the frame and the lid in the closedposition.

FIG. 10C is a cross sectional view similar to FIG. 10B but showing theassembly in the staged or second position where the lid is separatedfrom the peripheral portion of the frame.

FIG. 11 is a perspective view of an alternative assembly according toanother embodiment.

FIG. 12 is a top view of the assembly of FIG. 11 showing the tissuecassette and the frame in the open position ready to accept tissue inthe tissue cassette.

FIG. 13A is a cross sectional view of the assembly of FIG. 11 takengenerally along line 13A-13A of FIG. 12 showing the tissue cassette andthe frame in a partially closed position.

FIG. 13B is a cross sectional view of the assembly of FIG. 11 takengenerally along line 13B-13B of FIG. 12 but showing the assembly in astaged or second position where the lid is separated from the peripheralportion of the frame and a portion of the tissue cassette is ready to beembedded and then sectioned in a microtome.

FIG. 14A is a cross sectional perspective view of the assembly of FIG.11 taken generally along line 14A-14A of FIG. 12 and in the openposition.

FIG. 14B is a cross sectional perspective view similar to FIG. 14A butshowing the peripheral portion of the frame and the lid in the closedposition.

FIG. 14C is a cross sectional perspective view similar to FIG. 14 .B butshowing the assembly in the staged or second position where the lid isseparated from the peripheral portion of the frame.

FIG. 15 is an exploded perspective view of an alternative assemblyaccording to another embodiment.

FIG. 16A is detailed exploded perspective view of the lid and peripheralframe of FIG. 15 .

FIG. 16B is a detailed perspective view of a lid-frame connector of theassembly of FIG. 15 .

DETAILED DESCRIPTION

Referring first to FIGS. 1, 1A, and 2 , an assembly 10 constructed inaccordance with an illustrative embodiment of the invention is shown inthe open position. Assembly 10 includes a tissue sample cassette 12carried within and separably coupled to a frame 14, which includes aperipheral portion 16. A lid 18 is separably coupled to peripheralportion 16. While cassette 12 is shown to have a rectangularconfiguration, it will be recognized that cassette 12 may havealternative configurations. For example, a cassette may have a circularconfiguration. Peripheral portion 16 generally includes an interiordefined between surrounding (peripheral) walls 16 a, 16 b, 16 c, 16 d,and lid 18 is sized and configured to fit in the interior and isseparably coupled to at least one of the surrounding walls 16 a, 16 b,16 c, 16 d. The frame 14 generally includes an interior defined betweensurrounding outer walls 14 a, 14 b, 14 c, 14 d and a bottom edge 14 e,and the cassette 12 is sized and configured to move within the interiorbetween at least first and second positions, as generally discussed inthe above-incorporated patent properties and for the same purposes. Thefirst position is shown in FIGS. 3B and 3C, while the second, “staged”position is shown in FIG. 3D. In the second position, the lower portionof the cassette 12 is exposed below the bottom edge 14 e of the frame 14for allowing cassette 12 and an embedded tissue sample 44 to besectioned in a microtome while the frame 14 is held in the microtomechuck.

The connection of the tissue cassette 12 to the frame 14 may beaccomplished in many different manners, such as any of the mannersdescribed in the above-incorporated patent properties. Alternatively,the cassette 12 may be coupled to the frame 14 in other novel mannerssuch as described hereinbelow. In the illustrative embodiment of FIG. 1, cassette 12 is initially separably coupled to frame 14 throughframe-cassette connectors 64 that couple the surrounding walls 14 a, 14b, 14 c, 14 d to the cassette 12.

Referring to FIGS. 4A-4C and 5D, each frame-cassette connector 64includes a retaining structure (e.g., first retaining structure), suchas a pin 66, formed integrally with the frame 14 and extending at leastpartway through a retaining structure (e.g., second retainingstructure), such as a flange 68 formed integrally with the cassette 12,such as on a sidewall 12 a of cassette 12. Each pin 66 extends generallyupwardly from a tab 70, which extends generally laterally inwardly fromone of the outer walls 14 a, 14 b, 14 c, 14 d. Pin 66 includes a base 72disposed on tab 70, a tip 74 on an opposite surface of flange 68, and ashaft 76 extending from the base 72 to the tip 74 through flange 68. Tip74 may have a tip width 78 that is greater than a shaft width 80.Generally, because the tip 74 and the tab 70 are wider than the shaft76, and because the flange 68 extends within the recessed or undercutarea between the tip and the tab, the flange is retained on the pin 66by the tip and the tab. Accordingly, until the frame-cassette connector64 is separated (e.g., broken) during the staging operation as discussedin greater detail below, the flange 68 is secured to the pin 66. Pin 66may be formed as a right circular cylinder or conical frustrum have agenerally circular cross section. In this illustrative embodiment, thefirst retaining structure is a pin 66, but it will be understood that inother embodiments the first retaining structure may take other forms,such as any shape or structure configured to extend at least partwaythrough a corresponding second retaining structure (e.g., the flange 68formed integrally with the cassette 12) to attach or couple two or morecomponents. Such first retaining structures may include, for example andwithout limitation, a peg, a bar, a shaft, a stem, a stick, etc., andmay have any cross-sectional shape, such as generally circular,generally oval, or generally polygonal (e.g., generally square,pentagonal, hexagonal, etc.). Additionally, a first retaining structuremay be generally straight or may include one or more curves, bends, orangles.

Referring to FIGS. 4B (first position) and 4C (second position),frame-cassette connectors 64 of this illustrative embodiment arefrangible and are configured to break when cassette 12 is moved from thefirst position toward the second position. In the illustrativeembodiment, pin 66 tears out of flange 68, breaking flange 68, duringthis movement. In other embodiments with different relative sizes ormaterial choices for pin 66 and flange 68, pin 66 or tab 70 may breakbefore pin 66 tears out of flange 68. In other embodiments, variousconnectors, such as frame-cassette connectors and lid-frame connectors(discussed below), may be configured to separate without breaking. Forexample, some connectors may be configured to accommodate sufficientelastic deformation to allow a pin to be removed from a flange withoutbreakage of the pin, the tab, or the flange. Returning to theillustrative embodiment, as can be seen by comparing the orientation oftabs 70 FIGS. 4B and 4C, each tab 70 may be pivotably coupled to itsrespective outer wall 14 a, 14 b, 14 c, 14 d so that, during movementfrom the first position to the second position, tab 70 pivots downward,which may encourage predictable and consistent separation (e.g.,breakage) of frame-cassette connector 64 (e.g., pins 66 tearing-out offlanges 68).

The connection of the lid 18 to the peripheral portion 16 of the frame14 may be accomplished in many different manners, such as any of themanners described in the above-incorporated patent properties.Alternatively, the lid 18 may be coupled to the peripheral portion 16 ofthe frame 14 in other novel manners such as described hereinbelow. Inthe illustrative embodiment of FIG. 1 , lid 18 is initially separablycoupled to the peripheral portion 16 of the frame 14 through lid-frameconnectors 36 that couple the surrounding walls 16 a, 16 b, 16 c, 16 dto the lid 18.

Lid-frame connectors 36 may be generally similar in structure andoperation to the frame-cassette connectors 64 described above. Referringto FIGS. 4C and 5E, each lid-frame connector 36 includes a retainingstructure (e.g., first retaining structure), such as a pin 82, formedintegrally with the peripheral portion 16 of frame 14 and extending atleast partway through a retaining structure (e.g., second retainingstructure), such as a flange 84 formed integrally with the lid 18. Eachpin 82 extends generally downwardly from a tab 86, which extendsgenerally laterally inwardly from one of the surrounding walls 16 a, 16b, 16 c, 16 d. Pin 82 includes a base 88 (see FIG. 5E) disposed on tab86, a tip 90 on an opposite surface of flange 84, and a shaft 92extending from the base 88 to the tip 90 through flange 84. Tip 90 mayhave a tip width 94 that is greater than a shaft width 96. Pin 82 may beformed as a right circular cylinder or conical frustrum have a generallycircular cross section. In this illustrative embodiment, the firstretaining structure is a pin 82, but it will be understood that in otherembodiments the first retaining structure may take other forms, such asany shape or structure configured to extend at least partway through acorresponding second retaining structure (e.g., the flange 84 formedintegrally with the cassette 18) to attach or couple two or morecomponents. Such first retaining structures may include, for example andwithout limitation, a peg, a bar, a shaft, a stem, a stick, etc., andmay have any cross-sectional shape, such as generally circular,generally oval, or generally polygonal (e.g., generally square,pentagonal, hexagonal, etc.). Additionally, a first retaining structuremay be generally straight or may include one or more curves, bends, orangles.

Referring to FIGS. 4B (first position) and 4C (second position),lid-frame connectors 36 of this illustrative embodiment are frangibleand are configured to break when lid 18 is moved from the first positiontoward the second position. In the illustrative embodiment, pin 82 tearsout of flange 84, breaking flange 84, during this movement. In otherembodiments with different relative sizes or material choices for pin 82and flange 84, pin 82 or tab 86 may break before pin 82 tears out offlange 84. As can be seen by comparing the orientation of tabs 86 FIGS.4B and 4C, each tab 86 may be pivotably coupled to its respectivesurrounding wall 16 a, 16 b, 16 c, 16 d so that, during movement fromthe first position to the second position, tab 86 pivots downward, whichmay encourage predictable and consistent separation (e.g., breakage) oflid-frame connector 36 (e.g., pins 82 tearing-out of flanges 84).

Now referring to FIGS. 2, 3A and 3B, the connections between frame 14and peripheral portion 16 are described in more detail. Peripheralportion 16 is coupled to wall 14 a of frame 14 by a pair of hinges 22 a,22 b, which are optionally frangible. Peripheral portion 16 snap fitsinto the closed position (FIG. 3B) through the engagement of peripheralportion closure elements, which may include connectors such as latches24, 26 with frame closure elements, which may include connectors such asflanges 30, 32. Latch 24, which may be in the form of a hook, ispositioned on outer wall 16 a of peripheral portion 16 and engages withflange 30 of wall 14 a of frame 14 in the closed position. Latches 26are positioned on wall 16 c of peripheral portion 16 and engage (e.g.,snap fit) with a flange 32 of wall 14 c of frame 14 in the closedposition.

Now referring to FIGS. 1, 3A, and 3B, the connections between lid 18 andcassette 12 are described in more detail. Lid 18 snap fits into theclosed position (FIG. 3B) through the engagement of lid closureelements, which may include connectors, such as flanges 58, withcassette closure elements, which may include connectors, such as latches60. In this embodiment, lid 18 includes a pair of opposed flanges 58arranged to snap fit with two opposed pairs of latches 60 in the closedposition. In the closed position, with flanges 58 of lid 18 engaged withlatches 60 of cassette 12, lid 18 and cassette 12 are coupled togetherand move between the first position (FIG. 3C) and the second or stagedposition (FIG. 3D) as a single unit.

Cassette 12 and lid 18 are sized and configured to move within theinterior of frame 14 between at least first and second positions, asshown best in FIGS. 3C and 3D. Referring to FIGS. 2, 4B, and 4C, lid 18includes a lid retention flange 38 on each of its four corners.Retention flanges 38 are configured to engage with cassette positioningelements 40 of frame 14, which are formed as part of the interiorcorners of the four corners of frame 14. In the illustrative embodiment,each retention flange 38 engages with a respective cassette positioningelement 40. The cassette positioning elements 40 are flexible and hollowsuch that as the retention flanges 38 pass by the cassette positioningelements 40 (e.g., downwardly), the retention flanges 38 deform thecassette positioning elements 40 and ultimately “snap” below thecassette positioning elements 40 as shown, for example, in FIG. 4C.

As shown in FIGS. 2, and 4A-4C, each corner of frame 14 includes adiagonal stop 46 located beneath and spaced downwardly apart from therespective cassette positioning element 40. When cassette 12 reaches thesecond position, stops 46 prevent further downward movement of retentionflanges 38 of lid 18. Thus, in the second position, retention flanges 38of lid 18 are secured vertically between cassette positioning elements40 (on the top) and stops 46 (on the bottom). Because lid 18 andcassette 12 are coupled together by flanges 58 and latches 60, thisretains the cassette 12 and lid 18 in the second position and ready forembedding and subsequent microtome sectioning, as described in theabove-incorporated patent properties.

As shown in FIG. 3A, one or more tissue samples 44 may be placed incassette 12 that defines a recess or interior area 11 surrounded by atleast one sidewall 12 a and including a bottom wall 12 b. Although agenerally rectangular recess 11 is shown (see FIG. 2 ), it will beappreciated that any other shape, such as any polygon (e.g., square) orany rounded shape (e.g., oval or circular) or shapes with troughs oralignment features for the tissue sample 44 may be used instead.

This illustrative embodiment also includes a resilient structure carriedon the underside of the lid 18. The resilient structure is in the formof curved, resilient fingers 42 for purposes of allowing flexibleengagement between distal ends 42 a of the resilient fingers 42 and theone or more tissue samples 44 in the cassette 12. Resilient fingers 42form a compliant structure that holds the tissue 44 in the desiredorientation and position without creating an artifact impression on thetissue sample 44 during processing. Referring to FIG. 4A, in thisembodiment, distal ends 42 a of resilient fingers include tines 42 b,which may extend generally downward when lid 18 is in the closedposition. Tines 42 b may provide additional security against undesiredmovement of tissue sample 44.

It will be appreciated that different resilient finger 42 materials andconfigurations may be chosen based, for example, on the type of tissueto be processed and analyzed. For example, small mucosal tissue samplesmay be held and processed with success using some arrangements ofresilient fingers 42, while other types of tissue, such as fatty tissue,may be better served by another resilient finger 42 material orconfiguration. As another example, larger tissue samples may requireretention structure that operates well over a large surface area. Inaddition, resilient fingers 42 may have tissue specific orientation orholding alignment features to facilitate orientation of very specifictypes of tissue samples. Generally, resilient fingers may be disposed onthe lid in a uniform or non-uniform arrangement or orientation, may beformed (e.g., shape, thickness, or length), or may be otherwise modified(e.g., similar to configurations disclosed in the above-incorporatedpatent properties) as desired to facilitate accepting and retainingtissue samples of various types, sizes, or thicknesses.

Resilient fingers 42 allow infiltration of the solvents and chemicalsused to fix, process, and stain tissue, and of embedding material usedto embed the tissue while the tissue is retained by resilient fingers42. Resilient fingers 42 are flexible and configured to engage andretain tissue in place during processing and embedding. Further,resilient fingers 42 are capable of successful sectioning in themicrotome after the recess or interior area of cassette is filled withliquefied embedding material which subsequently hardens. Resilientfingers 42 may, for example, be formed of the same material as lid 18,such as a sectionable plastic.

With reference now to FIGS. 3B and 3C, assembly 10 is shown withperipheral portion 16 in the closed position and where cassette 12 andlid 18 are in a first position. Once the tissue 44 is loaded in theinterior or recess 11 of cassette 12, peripheral portion 16 may berotated to the closed position. Peripheral portion 16 rotates abouthinges 22 a, 22 b, which may be frangible, to move from the openposition to the closed position. If hinges 22 a, 22 b are frangible,such pivoting may sever hinges 22 a, 22 b. Peripheral portion 16 mayrotate until latches 24, 26 engage with flanges 30, 32 of frame 14,securely locking peripheral portion 16 to frame 14. With peripheralportion 16 in the closed position, resilient fingers 42 bias the tissuesample 44 towards bottom wall 12 b of cassette 12.

As further shown in FIGS. 3B and 3C, when lid 18 is closed, theresilient fingers 42 press against tissue sample 44 and deform threedimensionally around tissue sample 44 creating three dimensional spacesaround tissue sample 44 and essentially immobilizing tissue sample 44during the tissue processing and embedding procedures. This also ensuresthat the tissue sample 44 is held flat against bottom wall 12 b ofcassette 12 such that when microtome slices are made, progressively frombottom wall 12 b towards lid 18, complete and continuous sections oftissue sample 44 may be formed. Once all of sample 44 has been sliced,the next slice would contain only resilient structure 42 and embeddingparaffin wax.

Now referring to FIGS. 3D and 4C, assembly 10 is shown in which cassette12 and lid 18 are in the second position. Pressing lid 18 downwardcauses lid-frame connectors 36 and frame-cassette connectors 64 toseparate (as described above), allowing lid 18 and cassette 12 to movefrom the first position (FIG. 3C) towards the second position (FIG. 3D).Continued downward pressure on the lid 18 causes lid 18 to slide furtherdownward inside frame 14. During this downward movement, each corner ofthe lid 18 (e.g., retention flanges 38) engages with its respectivecassette positioning element 40 on the interior corner of the frame 14.As the retention flanges 38 pass by the cassette positioning elements40, they deform the cassette positioning elements 40 and ultimately“snap” below the cassette positioning elements 40 as shown in FIG. 4C,which prevents upward movement of lid 18 and cassette 12. When cassette12 reaches the second position, stops 46 prevent further downwardmovement of flanges 38 of lid 18. This retains the cassette 12 and lid18 in the second position during the embedding and subsequent microtomesectioning process.

In the second position, tissue sample 44, a portion of cassette 12, andportions of resilient fingers 42 are staged to be sectioned in amicrotome. Because cassette positioning elements 40 and stop 46 limitthe travel of lid 18 in the second position, cassette positioningelements 40 and stop 46 assure that cassette 12 is staged to apredetermined depth independent of the configuration of cassette 12.Staging to the predetermined depth ensures that the bottom wall 12 b ofthe cassette 12 is positioned as desired with respect to the embeddingmold 52, such as at a predetermined vertical spacing (see FIG. 3D). Thisfacilitates the use of automated microtomes in the processes describedbelow because the thickness of the embedding material that must beremoved before reaching the tissue sample 44 held against the bottomwall 12 b will be substantially the same for all cassettes.

Because there are millions of procedures completed each year utilizingassemblies like these, embodiments of the present invention are designedfor high production volumes and, consequently, are directed towards usein automated histopathology processes. One such process is automatedembedding. An exemplary automated embedding machine uses a motorizedstaging device 48 that pushes the cassette through the frame into theembedding mold 52 as shown in FIGS. 3C and 3D. A staging device 48 mayincorporate spring-loaded cylindrical fingers or feet which push the lid18 and cassette 12 through frame 14.

In use, one or more tissue samples 44 are placed within the interiorspace or recess and, specifically, on bottom wall 12 b of cassette 12 asshown in FIG. 3A. Tissue sample 44 is sized and oriented in cassette 12according to the required section plane desired by the pathologist foreach tissue sample 44. Peripheral portion 16 is then closed and snappedinto place such that resilient fingers 42 bear against and trap tissuesample 44 against bottom wall 12 b in the desired orientation as shownin FIG. 3B. Resilient fingers 42 may deform three dimensionally toaccommodate various sizes and shapes of tissue samples 44. The force ofresilient fingers 42 against tissue sample 44 should be enough toimmobilize tissue sample 44 and trap it against bottom wall 12 b, butnot enough to induce artifacts in tissue sample 44. At this point,assembly 10 with the trapped tissue sample 44 may be subjected to aconventional tissue processing operation that uses vacuum, heat andchemicals to remove the interstitial fluids within the tissue andreplace those fluids with a hardenable material, such as moltenparaffin. As mentioned above, during these processing steps, theresilient fingers 42 and bottom wall 12 b allow the fluids to reach andfully infiltrate into tissue sample 44.

The illustrated configuration of cassette 12, frame 14, and lid 18,including resilient fingers 42, is an improvement over assemblies thatrequire a complex lid adjustment procedure whereby the user must choosefrom a limited number of specific engagement distances between the lidand the cassette to ensure that the tissue sample 44 is properlyimmobilized against the bottom wall 12 b of the cassette. The specificengagement distances were determined by preset tabs in the interior ofthe cassette basket that engaged and retained the lid. By utilizing theillustrative embodiment, and particularly the resilient fingers 42 (orother similar tissue biasing structures disclosed herein), the complexadjustment procedure for the lid is eliminated. Accordingly, in someexemplary embodiments, lid closure and proper immobilization of thetissue sample (without excessive deformation) may be accomplished by asimple, “one-snap” procedure in which the lid is closed and theresilient fingers 42 (or other similar biasing structures) properly biasthe tissue sample 44 against the bottom wall 12 b of the cassette 12,regardless of the thickness of the tissue sample. It will be appreciatedthat other configurations and designs may be used to achieve similarpurposes.

After the tissue processing is complete, cassette 12 and frame 14 arethen placed into a suitable mold 52 and embedded in paraffin. Cassette12 and/or frame 14 may include machine-readable indicia allowing amachine to determine the type and size cassette 12 being used and tomake an appropriate decision as to which mold to place the cassette 12in for embedding. The entire assembly 10 including the exposed portionof cassette 12 is embedded within a hardened block of paraffin wax. Themold 52 may generally follow the contour of the bottom 12 b of cassette12, although the portion of the mold surrounding cassette 12 ispreferably square as opposed to round. This assists with the subsequentproduction of ribbon slices. This portion of the procedure may thereforebe similar to that disclosed in the above-incorporated patentproperties. As discussed therein, frame 14 is then used as a fixture formounting the embedded assembly 10 in a microtome. The necessary numberof slices are taken off of the exposed underside until enough sectionsor slices are taken and appropriately mounted on a microscope slide,stained and cover slipped.

Another method (not shown) of loading tissue sample 44 in assembly 10 ispossible. First, peripheral portion 16 is detached from frame 14, whichis set aside. Tissue sample 44 is placed onto resilient fingers 42, andthen frame 14 is installed on top of lid 18. When frame 14 is installedon top of peripheral portion 16, latches 24, 26 of peripheral portion 16engage with flanges 30, 32, respectively, of frame 14. In this manner,peripheral portion 16 is secured to frame 14. Assembly 10 may then bepositioned in its usual upright position while resilient lid 18 remainscoupled to frame 14 and resilient fingers 42 secure tissue sample 44 tobottom wall 12 b of cassette 12.

Generally, cassette 12 (and, in some embodiments, lid 18) may be formedof a relatively less rigid material and frame 14 (and, in someembodiments, lid 18) may be formed of a relatively more rigid material.Cassette 12 may be formed from a sectionable plastic, such asperfluoroalkoxyethylene (PFA), or polyethylene (PE)-based or containingmaterials in accordance with the above-incorporated patent properties.The material forming cassette 12 may be at least translucent so as to benon-distracting during tissue analysis. Frame 14, including peripheralportion 16, may be formed from a more rigid, less costly plastic, suchas acetal. Acetal is far easier to mold in large quantities or inmulti-cavity injection molds. As will be appreciated from FIG. 1A,cassette 12 may be molded separately from the frame 14 and then insertedinto the frame 14. Similarly, lid 18 may be molded separately from theperipheral portion 16 and then inserted into the peripheral portion 16.Further, when cassette 12 and frame 14 are made of materials withsignificantly different melting temperatures, they can be insert moldedor co-molded, such as using the two-shot technique described below inconnection with FIGS. 6A-6D. In some illustrative embodiments, thecassette 12, lid 18, and frame 14 may be combined into a single pieceprior to the customer receiving them, so the assembly arrives as asingle piece ready to load with tissue. This is advantageous over priorassemblies where the user was required to assemble the components beforeloading the tissue.

FIG. 5E shows the pin connector 36, which is structurally similar toconnector 64 but in a generally inverse configuration.

FIGS. 5A-5D illustrate an example assembly process, specificallypertaining to frame-cassette connectors 64. FIG. 5A shows the frame 14and the components integrally formed therewith, including tab 70 and pin66. Notably, pin 66 does not yet include its wide tip 74 (FIGS. 5C and5D). Pin 66 may be generally frustoconical, which may facilitate releaseof the mold used to form frame 14 and associated components. FIG. 5Bshows the cassette and the components integrally formed therewith,including flange 68 positioned with respect to pin 66 such that shaft 76of pin extends through flange 68. This may be accomplished by assemblinga separately molded frame 14 and cassette 12, or it may be accomplishedby sequentially molding the frame 14 and cassette 12 in place. FIG. 5Balso shows tool 98 approaching pin 66. FIG. 5C shows pin 66 with thedistal portion of its shaft 76 formed into a relatively wider tip 74 byoperation of tool 98. This deformation of pin 66 to form tip 74 securesflange 68 of cassette 12 to pin 66 of frame 14. In some exemplaryprocesses, the tip 74 may be formed by the tool 98 when the pin 66 is ata temperature above room temperature but below its melting temperatureso that the distal portion of the shaft 76 may be readily plasticallydeformed by the tool. FIG. 5D shows the completed frame-cassetteconnectors 64 as previously described. A generally similar,corresponding process may be used to assemble lid-frame connectors 36.

FIGS. 6A-6D, 7A-7C, and 7D-7F illustrate alternative example retainingstructures comprising pin/flange connectors and associated methods ofassembly. The examples described above with respect to FIGS. 5A-5E orany of the alternative examples described below with respect to FIGS.6A-6D, 7A-7C, and 7D-7F may be utilized in connection with variousembodiments according to the present disclosure. FIGS. 6A-6D are crosssectional views of an alternative pin/flange connector 600 showing stepsof a two-shot, co-molding process. In FIG. 6A, a pin 602 is formedintegrally with a first component 604, such as by injection molding.This operation may be referred to as a first molding operation or afirst shot. In the context of assembly 10 illustrated in FIG. 1 , firstcomponent 604 may be frame 14. In FIG. 6B, a mold/tool 612 is shownapproaching the first component 604. Referring to FIG. 6C, the mold/tool612 engages the first component 604 to deform the pin 602 to form awider, mushroom head shaped tip 614. In some exemplary processes, thetip 614 may be formed by the mold/tool 612 when the pin 602 is at atemperature above room temperature but below its melting temperature sothat the distal portion of the pin may be readily plastically deformedby the mold/tool. Additionally, the mold/tool 612 engages the firstcomponent 604 to at least partially define one or more cavities 610 formolding a second material. As shown in FIG. 6D, cavity 610 is filled ina second molding operation or second shot to form a flange 606, formedintegrally with a second component 608, disposed about pin 602.Generally, because the flange 606 extends within the recess or undercutbeneath the tip and surrounding the pin 602, the flange is secured tothe pin until the connector 600 is separated (e.g., broken) in thestaging operation. In the context of assembly 10 illustrated in FIG. 1 ,second component 608 may be cassette 12. Such a two-shot molding processmay be advantageous compared to some other potential assembly or moldingprocesses because it may involve fewer handling and assembly steps, forexample. In an exemplary two-shot processes, the first component 604 maybe formed in a mold. Without removing the first component 604 from themold, the mold may reconfigured (e.g., rotated 90 degrees) to receivemold/tool 612. Then, the second component 608 may be molded. Finally,the first component 604 and the second component 608, now connected, maybe removed. Accordingly, this exemplary two-shot process may not requiretransferring the first component from a first mold to a second mold orassembly of separately molded components.

In other exemplary processes, first component 604 may be formed and thenplaced into a second mold Then, second component 608 may be formed, suchas by injection molding, directly on first component 604, such as by aco-molding or insert molding process. Generally, first component 604 maybe shaped such that any cavities generally narrow with increasing depthto facilitate mold release. Similarly, pin 602 may be generallyfrustoconical, with the narrower end facing out, to facilitate moldrelease.

FIGS. 7A-7C are cross sectional views of an alternative pin/flangeconnector 700 showing steps of an assembly process. In FIG. 7A, a firstcomponent 702 includes a recess 704 into which a pin 706 is installedand secured. For example, the pin 706 may be secured in the recess 704using an adhesive. First component 702 may be formed of a firstmaterial, and pin 706 may be formed of a second material. Pin 706 may begenerally frustoconical and includes a recess 708 at its distal end. InFIG. 7B, a tool 710 is forming a tip 712 on pin 706. Tool 710 includes acentral projection 714 arranged to engage recess 708 of pin 706. In FIG.7C, a second component 716 (e.g., comprising a flange) has been moldedin the recess 704 around pin 706, such as by injection molding. Secondcomponent 716 may be formed of a third material. Accordingly, connector700 couples first component 702 and second component 716. Morespecifically, because the flange of the second component 716 extendswithin the recess or undercut beneath the tip 712 and surrounding thepin 706, the second component is secured to the first component 702until the connector 700 is separated (e.g., broken) in the stagingoperation.

FIGS. 7D-7F are cross sectional views of an alternative pin/flangeconnector 750 showing steps of an assembly process. Pin connector 750may be generally similar to pin connector 700, except that pin 756 maybe formed integrally with first component 752. In FIG. 7D, firstcomponent 752 includes a recess 754 within which a pin 756 is integrallyformed. First component 752 and pin 756 may be formed of a firstmaterial. Pin 756 may be generally frustoconical. In FIG. 7B, a tool 760is forming a tip 762 on pin 756. Alternatively, in some exemplaryembodiments having appropriate geometries, the tip 762 may be moldedduring the initial molding of the first component 752 so that the tool760 and separate tip-forming step may be omitted. In FIG. 7F, a secondcomponent 766 (e.g., comprising a flange) has been molded in the recess754 around pin 756, such as by injection molding in a second mold.Second component 766 may be formed of a second material. Accordingly,connector 750 couples first component 752 and second component 766. Morespecifically, because the flange of the second component 766 extendswithin the recess or undercut beneath the tip 762 and surrounding thepin 756, the second component is secured to the first component 752until the connector 750 is separated (e.g., broken) in the stagingoperation.

Although several exemplary processes for forming and assembling certainexemplary frame-cassette connectors, lid-frame connectors, and othercomponents are described herein, it is to be understood that variousdevices including such connectors and methods of using the devices maybe within the scope of this disclosure, regardless of whether thedevices are produced using the processes described above, conventionalprocesses, or future-developed processes, or any combination thereof.

FIGS. 8, 9, and 10A-10C depict another illustrative embodiment of anassembly 100 that is generally similar to assembly 10 shown anddescribed with respect to FIGS. 1, 1A, 2, 3A-3D, and 4A-4C. Likereference numerals refer to like structure shown and described above.Unless specifically indicated, the description of the structure andfunction or methodology of corresponding components with respect toassembly 10 generally applies to assembly 100. Therefore, repeatedexplanation of previously described structure and function ormethodology is not necessary. In this embodiment, the resilient fingers42 of assembly 10 have been replaced by a generally rectangular platen142 and biasing members 120. Further, assembly 100 includes a differentarrangement of lid closure elements and cassette closure elements.

The assembly 100 includes a tissue sample cassette 112 including arecess or interior area 111 surrounded by at least one sidewall 112 aand including a bottom wall 112 b. Cassette 112 is carried within andseparably coupled to a frame 114, which includes a peripheral portion116. A lid 118 is separably coupled to the peripheral portion 116.Peripheral portion 116 generally includes an interior defined betweensurrounding (peripheral) walls 116 a, 116 b, 116 c, 116 d, and lid 118is sized and configured to fit in the interior and is separably coupledto at least one of the surrounding walls 116 a, 116 b, 116 c, 116 d. Theframe 114 generally includes an interior defined between surroundingouter walls 114 a, 114 b, 114 c, 114 d and a bottom edge 114 e, and thecassette 112 is sized and configured to move within the interior betweenat least first and second positions, as generally described above inconnection with assembly 10 and for the same purposes. The firstposition is shown in FIG. 10B, while the second, “staged” position isshown in FIG. 10C in which the lower portion of the cassette 112 isexposed below the bottom edge 114 e of the frame 114 for allowingcassette 112 and embedded tissue sample to be sectioned in a microtomewhile the frame 114 is held in the microtome chuck.

The connection of the tissue cassette 112 to the frame 114 may beaccomplished in many different manners, such as any of the mannersdescribed above. In the illustrative embodiment of FIG. 8 , cassette 112is initially separably coupled to frame 114 through frame-cassetteconnectors 164 that couple the surrounding walls 114 a, 114 b, 114 c,114 d to the cassette 112. Frame-cassette connectors 164 are similar inconstruction and operation to frame-cassette connectors 64 describedabove in connection with assembly 10. In this illustrative embodiment,frame-cassette connectors 164 are frangible.

The connection of the lid 118 to the peripheral portion 116 of the frame114 may be accomplished in many different manners, such as any of themanners described above. In the illustrative embodiment of FIG. 8 , lid118 is initially separably coupled to the peripheral portion 116 of theframe 114 through lid-frame connectors 136 that couple the surroundingwalls 116 a, 116 b, 116 c, 116 d to the lid 118. Lid-frame connectors136 are similar in construction and operation to lid-frame connectors 36described above in connection with assembly 10. In this illustrativeembodiment, lid-frame connectors 136 are frangible.

Now referring to FIGS. 8 and 9 , the connections between frame 114 andperipheral portion 116 are shown in more detail. Peripheral portion 116is coupled to wall 114 a of frame 114 by a pair of hinges 122 a, 122 b,which are optionally frangible. Peripheral portion 116 snap fits intothe closed position (FIG. 10B) through the engagement of peripheralportion closure elements, such as latches 124, 126 with frame closureelements, such as flanges 130, 132. Latch 124 is positioned on outerwall 116 a of peripheral portion 116 and engages with flange 130 in wall114 a of frame 114 in the closed position. Latches 126 are positioned onwall 116 c of peripheral portion 116 and engage with flange 132 of wall114 c of frame 114 in the closed position.

Referring to FIGS. 8, 9, and 10A, the connections between lid 118 andcassette 112 are shown in more detail. Lid 118 snap fits into the closedposition (FIG. 10B) through the engagement of lid closure elements,which may include connectors, such as latches 158, with cassette closureelements, which may include connectors, such as flanges 160. In thisembodiment, each latch 158 is disposed on a respective extending arm159. The arms 159 extend generally downwardly from the lid 118 when thelid 118 is in the closed position. A corresponding pair of arms 159 andlatches 158 is disposed on each lateral side of lid 118, with the arms159 and latches 158 in each pair disposed on the lid in a spaced-apart,opposed arrangement such that latches 158 face each other. Each flange160 of cassette 112 is oriented generally laterally and is arranged toengage both latches 158 of a corresponding pair of arms 159. In theclosed position, with latches 158 of lid 118 engaged with flanges 160 ofcassette 112, lid 118 and cassette 112 are coupled together and movebetween the first position (FIG. 10B) and the second or staged position(FIG. 10C) as a single unit. Generally, the lid closure elements serveto secure the lid to the cassette and to prevent the lid and thecassette from separating after the lid has been closed onto thecassette, such as during the various processing operations. In someexemplary embodiments including lid-mounted components arranged to biasthe tissue sample against the bottom wall of the cassette, the lidclosure elements may be configured to withstand the correspondingreaction force that may tend to separate the lid from the cassette.

Cassette 112 and lid 118 are sized and configured to move within theinterior of frame 114 between at least first and second positions, asshown best in FIGS. 10B and 10C in a manner similar to that describedabove with respect to assembly 10. Lid 118 includes a lid retentionflange 138 on each of its four corners. Retention flanges 138 areconfigured to engage with cassette positioning elements 140 of frame114, which are formed as part of the interior corners of the fourcorners of frame 114. In the illustrative embodiment, each retentionflange 138 engages with a respective cassette positioning element 140.The cassette positioning elements 140 are flexible and hollow such thatas the retention flanges 138 pass by the cassette positioning elements140 (e.g., downwardly), the retention flanges 138 deform the cassettepositioning elements 140 and ultimately “snap” below the cassettepositioning elements 140 as shown, for example, in FIG. 10C.

As shown in FIGS. 9 and 10B, each corner of frame 114 includes adiagonal stop 146 located beneath and spaced downwardly apart from therespective cassette positioning element 140. When cassette 112 reachesthe second position, stops 146 prevent further downward movement ofretention flanges 138 of lid 118. Thus, in the second position,retention flanges 138 of lid 118 are secured vertically between cassettepositioning elements 140 (on the top) and stops 146 (on the bottom).Because lid 118 and cassette 112 are coupled together by latches 158 andflanges 160, this retains the cassette 112 and lid 118 in the secondposition, and ready for embedding and subsequent microtome sectioning,as described above.

Referring to FIGS. 8, 9, and 10A-10C, instead of the resilient fingers42 of assembly 10 described above, the lid 118 of this embodimentincludes a resilient structure comprising a platen 142 configured to bereceived within generally rectangular recess 111 of cassette 112. Platen142 is generally rectangular and is coupled to a peripheral portion 117of the lid 118 by a plurality of biasing members 120. Biasing members120 are arranged to bias the platen 142 towards bottom wall 112 b ofcassette 112 when the lid 118 is in the closed configuration. In thisembodiment, the biasing members 120 are disposed in a generallyperpendicular arrangement between platen 142 and the peripheral portion117 of the lid 118.

Generally, biasing members 120 are elastically deformable to allowflexible engagement between platen 142 and the one or more tissuesamples in the recess 111 of cassette 112. Platen 142 and biasingmembers 120 form a compliant structure that holds the tissue in thedesired orientation without creating an artifact impression on thetissue sample during processing. Although a generally rectangular recess111 is shown, it will be appreciated that any other shape, such as anypolygon (e.g., square) or any rounded shape (e.g., oval or circular) orshapes with troughs or alignment features for the tissue sample may beused instead.

Platen 142 allows infiltration of the solvents and chemicals used tofix, process, and stain tissue, and of embedding material used to embedthe tissue while the tissue is retained by platen 142. Platen 142 isflexible and configured to engage and retain tissue in place duringprocessing and embedding. Further, platen 142 is capable of successfulsectioning in the microtome after the recess 111 or interior area ofcassette is filled with liquefied embedding material which subsequentlyhardens. Platen 142 may, for example, be formed of the same material aslid 118, such as a sectionable plastic.

Referring to FIG. 10A, in this embodiment, the tissue-contacting side ofplaten 142 includes tines 142 b, which may extend generally downwardwhen lid 118 is in the closed position. Tines 142 b may provideadditional security against undesired movement of the tissue samples.

Generally, assembly 100 is loaded with tissue, moved from the openposition to the closed position (including breaking frangible lid-frameconnectors 136 and frame-cassette connectors 164), staged, and otherwiseused in a manner similar to assembly 10 described above. In use, one ormore tissue samples are placed within the interior space or recess 111and, specifically, on bottom wall 112 b of cassette 112. The tissuesample is sized and oriented in cassette 112 according to the requiredsection plane desired by the pathologist. Peripheral portion 116 is thenclosed and snapped into place such that platen 142 bears against andtraps the tissue sample against bottom wall 112 b in the desiredorientation. Biasing members 120 deform to allow platen 142 toaccommodate various sizes and shapes of tissue samples. The force ofplaten 142 against the tissue sample should be enough to immobilize thetissue sample but not enough to induce artifacts in the tissue sample.At this point, assembly 100 with the trapped tissue sample may besubjected to a conventional tissue processing operation that usesvacuum, heat and chemicals to remove the interstitial fluids within thetissue and replace those fluids with a hardenable material, such asmolten paraffin. As mentioned above, during these processing steps, theplaten 142 and bottom wall 112 b allow the fluids to reach and fullyinfiltrate into tissue sample. In addition, platen 142 traps the tissuesample flat against bottom wall 112 b without leaving artifacts ormarkings on the tissue that might interfere with subsequent analysisunder a microscope. It will be appreciated that different biasing member120 and platen 142 materials and configurations may be chosen based, forexample, on the type of tissue to be processed and analyzed. Forexample, small mucosal tissue samples may be held and processed withsuccess using some arrangements, while other types of tissue, such asfatty tissue, may be better served by another material or configuration.For example, the thickness, shape, and number of biasing members may beselected to provide a desired immobilizing force on the tissue samples.

After the tissue processing is complete, cassette 112 and frame 114 arethen placed into a suitable mold and embedded in paraffin. Cassette 112and/or frame 114 may include machine-readable indicia allowing a machineto determine the type and size cassette 112 being used and to make anappropriate decision as to which mold to place the cassette 112 in forembedding generally in the manner described above with reference toassembly 10.

FIGS. 11, 12, 13A, 13B, and 14A-C depict another illustrative embodimentof an assembly 200 that is similar to assembly 100 shown and describedwith respect to FIGS. 8, 9, and 10A-10C, as well as assembly 10. Likereference numerals in FIGS. 11, 12, 13A, 13B, and 14A-C refer to likestructure shown and described above. Unless specifically indicated, thedescription of the structure and function or methodology ofcorresponding components with respect to assembly 100 and assembly 10generally applies to assembly 200. Therefore, repeated explanation ofpreviously described structure and function or methodology is notnecessary. In this embodiment, the generally rectangular platen 142 ofassembly 100 has been replaced by generally circular platen 242, and thegenerally perpendicular biasing members 120 of assembly 100 have beenreplaced by generally helical biasing members 220. Further, assembly 200includes a different arrangement of lid closure elements and cassetteclosure elements.

The assembly 200 includes a tissue sample cassette 212 including arecess or interior area 211 surrounded by at least one sidewall 212 aand including a bottom wall 212 b. Cassette 212 is carried within andseparably coupled to a frame 214, which includes a peripheral portion216. A lid 218 is separably coupled to the peripheral portion 216.Peripheral portion 216 generally includes an interior defined betweensurrounding (peripheral) walls 216 a, 216 b, 216 c, 216 d, and lid 218is sized and configured to fit in the interior and is separably coupledto at least one of the surrounding walls 216 a, 216 b, 216 c, 216 d. Theframe 214 generally includes an interior defined between surroundingouter walls 214 a, 214 b, 214 c, 214 d and a bottom edge 214 e, and thecassette 212 is sized and configured to move within the interior betweenat least first and second positions, as generally described above inconnection with assembly 100 and for the same purposes. The firstposition is shown in FIG. 14B, while the second, “staged” position isshown in FIG. 14C in which the lower portion of the cassette 212 isexposed below the bottom edge 214 e of the frame 214 for allowingcassette 212 and embedded tissue sample to be sectioned in a microtomewhile the frame 214 is held in the microtome chuck.

The connection of the tissue cassette 212 to the frame 214 may beaccomplished in many different manners, such as any of the mannersdescribed above. In the illustrative embodiment of FIG. 11 , cassette212 is initially separably coupled to frame 214 through frame-cassetteconnectors 264 that couple the surrounding walls 214 a, 214 b, 214 c,214 d to the cassette 212. Frame-cassette connectors 264 are similar inconstruction and operation to frame-cassette connectors 164 describedabove in connection with assembly 100. In this illustrative embodiment,frame-cassette connectors 264 are frangible.

The connection of the lid 218 to the peripheral portion 216 of the frame214 may be accomplished in many different manners, such as any of themanners described above. In the illustrative embodiment of FIG. 11 , lid218 is initially separably coupled to the peripheral portion 216 of theframe 214 through lid-frame connectors 236 that couple the surroundingwalls 216 a, 216 b, 216 c, 216 d to the lid 218. Lid-frame connectors236 are similar in construction and operation to lid-frame connectors136 described above in connection with assembly 100. In thisillustrative embodiment, lid-frame connectors 236 are frangible.

Now referring to FIGS. 11, 12, and 13A, the connections between frame214 and peripheral portion 216 are shown in more detail. Peripheralportion 216 is coupled to wall 214 a of frame 214 by a pair of hinges222 a, 222 b, which are optionally frangible. Peripheral portion 216snap fits into the closed position (FIG. 14B) through the engagement ofperipheral portion closure elements, such as latches 224, 226 with frameclosure elements, such as flanges 230, 232. Latch 224 is positioned onouter wall 216 a of peripheral portion 216 and engages with flange 230in wall 214 a of frame 214 in the closed position. Latches 226 arepositioned on wall 216 c of peripheral portion 216 and engage with aflange 232 of wall 214 c of frame 214 in the closed position.

Referring to FIGS. 11, 12, and 14A, the connections between lid 218 andcassette 212 are shown in more detail. Lid 218 snap fits into the closedposition (FIG. 14B) through the engagement of lid closure elements,which may include connectors, such as latches 258, with cassette closureelements, which may include connectors, such as flanges 260. In thisembodiment, each of four latches 258 is disposed on a respectiveextending arm 259. The arms 259 extend generally downwardly from the lid218 when the lid 218 is in the closed position. The arms 259 aredisposed in a spaced-apart arrangement generally surrounding platen 242,and latches 258 face generally laterally outwards from their respectivearms. Each of the four flanges 260 of cassette 212 is oriented generallylaterally and is arranged to engage one latch 258. In the closedposition, with latches 258 of lid 218 engaged with flanges 260 ofcassette 212, lid 218 and cassette 212 are coupled together and movebetween the first position (FIG. 14B) and the second or staged position(FIG. 14C) as a single unit.

Cassette 212 and lid 218 are sized and configured to move within theinterior of frame 214 between at least first and second positions, asshown best in FIGS. 14B and 14C in a manner similar to that describedabove with respect to assembly 100. Lid 218 includes a lid retentionflange 238 on each of its four corners. Retention flanges 238 areconfigured to engage with cassette positioning elements 240 of frame214, which are formed as part of the interior corners of the fourcorners of frame 214. In the illustrative embodiment, each retentionflange 238 engages with a respective cassette positioning element 240.The cassette positioning elements 240 are flexible and hollow such thatas the retention flanges 238 pass by the cassette positioning elements240 (e.g., downwardly), the retention flanges 238 deform the cassettepositioning elements 240 and ultimately “snap” below the cassettepositioning elements 240 as shown, for example, in FIG. 14C.

As best shown in FIG. 14A, each corner of frame 214 includes a diagonalstop 246 located beneath and spaced downwardly apart from the respectivecassette positioning element 240. When cassette 212 reaches the secondposition, stops 246 prevent further downward movement of retentionflanges 238 of lid 218. Thus, in the second position, retention flanges238 of lid 218 are secured vertically between cassette positioningelements 240 (on the top) and stops 246 (on the bottom). Because lid 218and cassette 212 are coupled together by latches 258 and flanges 260,this retains the cassette 212 and lid 218 in the second position, andready for embedding and subsequent microtome sectioning, as described inthe above-incorporated patent properties.

Referring to FIGS. 11, 12, 13A, 13B, and 14A-14C, instead of generallyrectangular platen 142 of assembly 100 described above, the lid 218 ofthis embodiment includes a resilient structure comprising a generallycircular platen 242 configured to be received within generally circularrecess 211 of cassette 212. Platen 142 is coupled to a peripheralportion 217 of the lid 218 by a plurality of biasing members 220.Biasing members 220 are arranged to bias the platen 242 towards bottomwall 212 b of cassette 212 when the lid 218 is in the closedconfiguration. In this embodiment, the biasing members 220 are disposedin an angled arrangement, and, more specifically, a generally helicalarrangement between platen 242 and the peripheral portion 217 of the lid218.

Generally, biasing members 220 are elastically deformable to allowflexible engagement between platen 242 and the one or more tissuesamples in the recess 211 of cassette 212. Platen 242 and biasingmembers 220 form a compliant structure that holds the tissue in thedesired orientation without creating an artifact impression on thetissue sample during processing. Although a generally circular recess211 is shown, it will be appreciated that any other shape, such as anypolygon (e.g., square or rectangle) or any rounded shape (e.g., oval) orshapes with troughs or alignment features for the tissue sample, may beused instead.

Platen 242 allows infiltration of the solvents and chemicals used tofix, process, and stain tissue, and of embedding material used to embedthe tissue while the tissue is retained by platen 242. Platen 242 isflexible and configured to engage and retain tissue in place duringprocessing and embedding. Further, platen 242 is capable of successfulsectioning in the microtome after the recess 211 or interior area ofcassette is filled with liquefied embedding material which subsequentlyhardens. Platen 242 may, for example, be formed of the same material aslid 218, such as a sectionable plastic.

Referring to FIG. 14A, in this embodiment, the tissue-contacting side ofplaten 242 includes tines 242 b, which may extend generally downwardwhen lid 218 is in the closed position. Tines 242 b may provideadditional security against undesired movement of the tissue sample.

Generally, assembly 200 is loaded with tissue, moved from the openposition to the closed position (including breaking frangible lid-frameconnectors 236 and frame-cassette connectors 264), staged, and otherwiseused in a manner similar to assembly 100 and assembly 10 describedabove. In use, one or more tissue samples are placed within the interiorspace or recess 211 and, specifically, on bottom wall 212 b of cassette212. The tissue sample is sized and oriented in cassette 212 accordingto the required section plane desired by the pathologist. Peripheralportion 216 is then closed and snapped into place such that platen 242bears against and traps the tissue sample against bottom wall 212 b inthe desired orientation. Biasing members 220 may deform to allow platen242 to accommodate various sizes and shapes of tissue samples. The forceof platen 242 against the tissue sample should be enough to immobilizethe tissue sample but not enough to induce artifacts in the tissuesample. At this point, assembly 200 with the trapped tissue sample maybe subjected to a conventional tissue processing operation that usesvacuum, heat and chemicals to remove the interstitial fluids within thetissue and replace those fluids with a hardenable material, such asmolten paraffin. As mentioned above, during these processing steps, theplaten 242 and bottom wall 212 b allow the fluids to reach and fullyinfiltrate into tissue sample. In addition, platen 242 traps the tissuesample flat against bottom wall 212 b without leaving artifacts ormarkings on the tissue that might interfere with subsequent analysisunder a microscope. It will be appreciated that different biasing member220 and platen 242 materials and configurations may be chosen based, forexample, on the type of tissue to be processed and analyzed. Forexample, small mucosal tissue samples may be held and processed withsuccess using some arrangements, while other types of tissue, such asfatty tissue, may be better served by another material or configuration.For example, the thickness, shape, and number of biasing members 220 maybe selected to provide a desired immobilizing force on the tissuesamples.

After the tissue processing is complete, cassette 212 and frame 214 arethen placed into a suitable mold and embedded in paraffin. Cassette 212and/or frame 214 may include machine-readable indicia allowing a machineto determine the type and size cassette 212 being used and to make anappropriate decision as to which mold to place the cassette 212 in forembedding generally in the manner described above with reference toassembly 100 and assembly 10.

FIGS. 15, 16A, and 16B depict another illustrative embodiment of anassembly 300 that is generally similar to assembly 10 shown anddescribed with respect to FIGS. 1, 1A, 2, 3A-3D, and 4A-4C, as well asother illustrative embodiments described herein. Like reference numeralsrefer to like structure shown and described above. Unless specificallyindicated, the description of the structure and function or methodologyof corresponding components with respect to assembly 10 and otherillustrative embodiments generally applies to assembly 300. Therefore,repeated explanation of previously described structure and function ormethodology is not necessary.

In assembly 300, the lid-frame connectors 36 and frame-cassetteconnectors 64 of assembly 10 have been replaced by lid-frame connectors336 and frame-cassette connectors 364, respectively, which generallycomprise inverted versions of lid-frame connectors 36 and frame-cassetteconnectors 64. Also, assembly 300 includes stress risers 385 in flanges384. Further, assembly 300 includes peripheral portion closure elements(e.g., latches 25 and flanges 31) arranged to couple lateral sidesurrounding (peripheral) walls 316 b, 316 d to lateral side surroundingouter walls 314 b, 314 d, respectively. Any one or more of thesefeatures may be optionally included in any other exemplary embodiment.

The assembly 300 includes a tissue sample cassette 312 generally similarto sample cassette 12. Cassette 312 is carried within and separablycoupled to a frame 314, which includes a peripheral portion 316 andwhich is generally similar to frame 14 and peripheral portion 16. A lid318 (generally similar to lid 18) is separably coupled to the peripheralportion 316. Peripheral portion 316 generally includes an interiordefined between surrounding (peripheral) walls 316 a, 316 b, 316 c, 316d, and lid 318 is sized and configured to fit in the interior and isseparably coupled to at least one of the surrounding walls 316 a, 316 b,316 c, 316 d. The frame 314 generally includes an interior definedbetween surrounding outer walls 314 a, 314 b, 314 c, 314 d, and thecassette 312 is sized and configured to move within the interior betweenat least first and second positions, as generally described above inconnection with assembly 10 and for the same purposes.

The connection of the tissue cassette 312 to the frame 314 may beaccomplished in many different manners, such as any of the mannersdescribed above. In the illustrative embodiment of FIG. 15 , cassette312 is initially separably coupled to frame 314 through frame-cassetteconnectors 364 that couple the surrounding walls 314 a, 314 b, 314 c,314 d to the cassette 312. Frame-cassette connectors 364 are similar inconstruction and operation to frame-cassette connectors 64 describedabove in connection with assembly 10, except that their orientation isinverted.

Specifically, each frame-cassette connector 364 includes a retainingstructure (e.g., first retaining structure), such as a pin 366, formedintegrally with the frame 314 and extending at least partway through aretaining structure (e.g., second retaining structure), such as a flange368 formed integrally with the cassette 312. Each pin 366 extendsgenerally downwardly (as compared to generally upwardly in assembly 10)from a tab 370, which extends generally laterally inwardly from one ofthe outer walls 314 a, 314 b, 314 c, 314 d. Generally, because the tipof the pin 366 and the tab 370 are wider than the shaft extendingtherebetween, and because the flange 368 extends within the recessed orundercut area between the tip and the tab, the flange is retained on thepin by the tip and the tab. Accordingly, until the frame-cassetteconnector 364 is separated (e.g., broken) during the staging operation,the flange 368 is secured to the pin 366.

The frame-cassette connectors 364 of this illustrative embodiment arefrangible and are configured to break when cassette 312 is moved fromthe first position toward the second position as described above inconnection with assembly 10. In this illustrative embodiment, pin 366tears out of flange 368, breaking flange 368, during this movement. Eachtab 370 may be pivotably coupled to its respective outer wall 314 a, 314b, 314 c, 314 d so that, during movement from the first position to thesecond position, tab 370 pivots downward, which may encouragepredictable and consistent separation (e.g., breakage) of frame-cassetteconnector 364 (e.g., pins 366 tearing-out of flanges 368).

The connection of the lid 318 to the peripheral portion 316 of the frame314 may be accomplished in many different manners, such as any of themanners described above. In the illustrative embodiment of FIG. 15 , lid318 is initially separably coupled to the peripheral portion 316 of theframe 314 through lid-frame connectors 336 that couple the surroundingwalls 316 a, 316 b, 316 c, 316 d to the lid 318. Lid-frame connectors336 are similar in construction and operation to lid-frame connectors 36described above in connection with assembly 10, except that theirorientation is inverted.

Specifically, lid-frame connectors 336 may be generally similar instructure and operation to the frame-cassette connectors 364 describedabove. Each lid-frame connector 336 includes a retaining structure(e.g., first retaining structure), such as a pin 382, formed integrallywith the peripheral portion 316 of frame 314 and extending at leastpartway through a retaining structure (e.g., second retainingstructure), such as a flange 384 formed integrally with the lid 318. Inthe open position, each pin 382 extends generally downwardly (ascompared to generally upwardly in assembly 10) from a tab 386, whichextends generally laterally inwardly from one of the surrounding walls316 a, 316 b, 316 c, 316 d. Similarly, in the closed configuration(e.g., similar to FIG. 3B), the pins 382 extend generally upwardly fromthe tabs 386. Pin 382 includes a base disposed on tab 386, a tip on anopposite surface of flange 384, and a shaft extending from the base tothe tip through flange 384.

Lid-frame connectors 336 of this illustrative embodiment are frangibleand are configured to break when lid 318 is moved from the firstposition toward the second position as described above in connectionwith assembly 10. In this illustrative embodiment, pin 382 tears out offlange 384, breaking flange 384, during this movement. Each tab 386 maybe pivotably coupled to its respective surrounding wall 316 a, 316 b,316 c, 316 d so that, during movement from the first position to thesecond position, tab 386 pivots downward, which may encouragepredictable and consistent separation (e.g., breakage) of lid-frameconnector 336 (e.g., pins 382 tearing-out of flanges 384).

Any exemplary frangible connectors described herein may include one ormore stress risers arranged to encourage a particular failure mode, suchas which component of the connector will break first and/or the locationof the break. FIG. 16 illustrates an exemplary stress riser,specifically a notch 385, in flange 384. During staging (e.g., movementfrom the first position to the second position), the notch 385 mayencourage breakage of the flange 384, thereby facilitating predictableand consistent separation of the lid 318 from the peripheral portion 316of frame 314.

Returning to FIG. 15 , the peripheral portion 316 snap fits into theclosed position (e.g., similar to FIG. 3B) through the engagement ofperipheral portion closure elements, such as latches 25 with frameclosure elements, such as flanges 31. In assembly 300, latches 25 extendfrom the lateral side surrounding walls 316 b, 316 d and thecorresponding flanges 31 are disposed on the lateral side surroundingouter walls 314 b, 314 d. In various embodiments, closure elements onthe lateral side walls (e.g., latches 25 and flanges 31) may be providedin addition to or in place of closure element on the end walls (e.g.,latches 24, 26 and flanges 30, 32 of assembly 10).

While the present invention has been illustrated by the description ofspecific embodiments thereof, and while the embodiments have beendescribed in considerable detail, it is not intended to restrict or inany way limit the scope of the appended claims to such detail. Thevarious features discussed herein may be used alone or in anycombination within and between the various embodiments. Additionaladvantages and modifications will readily appear to those skilled in theart. The invention in its broader aspects is therefore not limited tothe specific details, representative apparatus and methods andillustrative examples shown and described. Accordingly, departures maybe made from such details without departing from the scope or spirit ofthe general inventive concept.

What is claimed is:
 1. A method for preparing one or more biopsy tissuesamples for histological examination, the method comprising: positioninga tissue sample in a tissue cassette having a recess including at leastone side wall and a bottom wall, the tissue cassette formed of a firstmaterial that can be successfully sectioned in a microtome and isresistant to degradation from solvents and chemicals used to fix,process and stain tissue, the tissue cassette being disposed in a frameincluding a bottom edge, the tissue cassette being coupled to the frameby a frame-cassette connector including a first retaining structureformed integrally with the frame extending through a second retainingstructure formed integrally with the cassette; closing a peripheralportion of the frame, the peripheral portion of the frame including acassette lid disposed therein; moving the lid and the tissue cassettefrom a first position to a second position with respect to the frameincluding breaking the frame-cassette connector, wherein, in the secondposition, the bottom wall and at least a portion of the side wall extenddownwardly beyond the bottom edge of the frame for sectioning in themicrotome.
 2. The method of claim 1, wherein the first retainingstructure comprises a pin formed integrally with the frame and thesecond retaining structure comprises a flange formed integrally with thecassette.
 3. The method of claim 1, wherein the moving operationincludes breaking a lid-frame connector comprising a third retainingstructure formed integrally with the peripheral portion of the frameextending through a fourth retaining structure formed integrally withthe lid.
 4. The method of claim 3, wherein the third retaining structurecomprises a pin formed integrally with the peripheral portion of theframe and the fourth retaining structure comprises a flange formedintegrally with the lid.
 5. The method of claim 1, wherein the frame isformed of a second material different from the first material and morerigid than the first material; and the lid is formed of the firstmaterial.
 6. The method of claim 1, wherein closing a peripheral portionof the frame includes securing the tissue sample in the recess using aplaten mounted to the lid by a plurality of biasing members arranged tobias the platen toward the bottom wall of the recess.